9
®
RS485 TERM (RS485 serial communications termination resistor)
The position of this link is important only
if the RS485 serial communications are to
be used. The two units at the end of the
communications bus should have this link
set to the IN position. All other units
should have the link set to the OUT posi-
tion. If only two units are on the communications bus, set the links on both units to the IN position.
This link is LK1 on the burner interface board.
SERVO-MOTOR SELECTION
Motor Requirements
Since the servo-motors are not always supplied as part of the 5000 system, a few guidelines are
useful when selecting suitable motors other than those supplied by Fireye.
•
All servo-motors must be of the same operating voltage, not exceeding 250V rms / 50V rms
depending on board type.
•
All motors must be AC
•
The servo-motor current must not exceed 150mA rms / 750mA rms depending on board type.
•
If the motor voltage is lower than the mains supply voltage then a suitable power supply (such
as a transformer) must be provided
•
The motor supply to the 5000 must be protected with a suitable fuse for the motors being used.
The fuse must not exceed 3A
to ensure that damage to the control unit does not occur
•
The servo-motor time for 90° movement must not be less than 10 seconds or more than 60 sec-
onds
•
All servo-motors must have internal limit switches fitted which are adjusted to prevent exces-
sive rotation
•
All servo-motors must be able to drive the load imposed on them
•
All servo-motors must have suitable protection for the burner environment (for example, IP65
for applications exposed to the weather).
If in any doubt about a particular servo-motor’s suitability, seek confirmation from your equip-
ment supplier, who have a list of suitable motors.
Potentiometer requirements
All servo-motor potentiometers should be good quality plastic film types, with high resolution.
Depending on the supply voltage, a minimum resistance is allowed for the feedback potentiometers
to prevent excessive current consumption. See section 1 - Potentiometer supply voltage on page 8 for
details.
The potentiometer must be securely fixed to the output shaft of the gearbox in such a way as to give
accurate indication of the shaft position under all conditions and at all times.
IN
OUT
RS485
TERM
IN
OUT
RS485
TERM
IN
OUT
RS485
TERM
PC
